Means for controlling and measuring gas supply



Ap' 17, 192s.

" T. H. CLEMENTS I MEANS FOR CONTROLLING `AND MEASURING GAS SUPPLY Filed( Jan. 11. 192s A TTORNE Y.

Patented Apr. 17, 1928.

unirse Ar as.x

1,666,481c Parent-'r o1=ricav THOMAS, H. GLJEAVIENTIS;4 OFLOS ANGELESy CALIFORNIA@ AAASSIGNQR?0F UNIL-HALE. T0 ELC. MILLARD 'ENGINEERING COMPANY, OELOS AI1'GELES,-GALIFORNIAJT,A\Gone` EORATION OF. CALIFORNIA;

MEANS. FOR CONTROLLING ANDMEASURING.GASSUPPIHY.

Application inea January 1i, 192s. serial No.-so;46s:

This invention relates to means for con'- trolling and'measuring the supplyof gas throughv one or more connected,supply-lines and tlie-main object of the invention vis tol 5 provide an improved .means for this. purpose. An important application of my invention is in connection with the supply of gas such as fuel gas or illuminating gas to a distributing main. In such cases tlie flow of gas varies considerably 'from time to time, and it is customary to provide a small capacity meter lor operation at low rates ofy supply anda large capacity meter for operation at higher rates of. supply and to direct the l5 vgas i'lovv7 `either manually or automatically through one or the other ofsaid meters according' totheexisting rateot supply. A

particular object of my inventionis to..pro

vide in connection with a system of 'this type an. apparatus of improved construction whereby the flow ofIv gas is automatically,

transferred fromfthe smallfcapacity. meter to the large capacity nieterwlien .the rate of:

gas fiowreaches certain amount and. is

l5 automatically returned tothe small capacityv meter Whenthe rate 'of' gas loivufalls .belowA a certain amount. Av further object ofthe invention is to provide eiiicientnieans whereby the. gas stream is at all times directed, substantially Wholly through .which everfone` of the metersis in operationso as to prevent.

simultaneous partial flow through. both meters ivitliresultmg inaccuracies inmeasureinent.

heretofore been used for automaticallycontrolling the flow of gas through one -or the. other o't'the meters have been of such type for substantially complete transfer of, the.

QU gas stream fronione meter tothe other` I overcome. this disadvantage. According to my. invention the gas vflow iseither.suh'stan-` tially wholly through. the large= capacity meter orV not at allthrouglrsuch.meter so Sonie ofthe devices which have.l

tliat the inaccurate measurementreadings dueto'- passage-1 of small amounts 'of2- gas. through the largeI capacityl meterfare elimiiia-ted.

A- i'irther'object of myv invention is' to pro-vide an improved typeof differential 60 reliefvalvef for controllingftl're-low ofgas` toHon-e orI theother-of said meters. TheA relief valveaceording to -myI invention, a1-v thoug-h 1 iti-sparticularly advantageous foruse in this connectioiimay also bel usedifor 05 other-I purposes wherethe flowI of' gas; isto be transferred; between two ormorel con-y necting lines.

The accompanying drawings illustrate ein-- bodiments of myfin'verition-and referringo thereto:Y

Fig.'- 1-is a diagrammatic view of means according-to my inventionU for controlling; andi accuratelymeasuringfthe supply of Y gas for-'example toa distributingmain.

Fig: ,2 is -av vertical section ofi a form v ofl differentialrelef valve1 according to my invention:

Figs. 3and 'Y1-'are vertical'fsections ofmodi- .fied forms rofdifterential 'reliefivalve-.

The general applications ofy my inventionis `illust-,rated 'fin`- Fig.' 1: wherein 'y 1 designates a. gas supplyI pipe leadingfrom any'sou-rceofV illuminating.: or` other Y gas for exam le nautraltgas, oil'lgas, WaterA gas', etcr, an 2- 85 designates-.an outlet pipeleading; to adistributing mainor otherfmeans. forsu lying, the gas to* points offconsuinption.-l vo gas meters 3 ,and ,'4 are connected to the. respective pipeslY and 2; gas Ameter 3 being off'af 00 relatively smallcapacity forl exampleup to 15. cu. ft. per second'andigas `meter.y 4being ot' relatively large capacity'` say' from 10 to` 50' ciLxft: per: second.- Means areV rovided in the connections 5i andleading Y'omrtl're' l pipe 1 through meter 3 tothe outlet2gfor interposinga definite resistance to the. fiow of' gas through this;connection including meter 3, this meansconsisting, for example,` of an orifice device such asis generally. used for thisA purpose andcomprisng a chamber connectediatopposite ends to the pipe 5' leadilig `from the supply pipe 1 and'to .a pipe 'leadingA to the meter 3', saidfcli'amber havingsa.- partition indicatedin dotted lines at 105 8 provi-ded with an orifice 9.

AA4 pipe 1() leadsfrom supply pipe 1 to a dili'er'ential' relief" valve 11 andL from such' diderential reliet valve a pipe 12 leads to the large capacity meter 4 from which a pipe 14 leads to the outlet pipe 2. Manual control valves 14 and 15 may be provided in the respective pipe connections 6 and 13.

The function of the diierential relief valve is to control the gas tlow through the respective branches including the vsmall capacity meter 3 and the large capacity meter-4 in such manner that below a certain critical pressure diliierence between the supply pipe 1 and the outlet pipe 2 the iow will be substantially con'ined to the branch including the small capacity meter 3 whereas when the pressure diti'erence exceeds a certain valve the flow will be substantially diverted to the branch including the large capacity meter. Various terms ot' valves may be used for this purpose i'or example, the form shown in Fig. 2 comprising a cylindrical casing 13 connected at its lower and upper ends vrespectively to headers 19 and 2O to which are also secured the respective pipes 10 and 12 aforesaid. Within the casing 18 is mounted a cylinder or tubular member 22 supported in iixed position within the casing for example by webs or studs 21 and 21 and formed with horizontal partition 23 which divides the space within the cylinder 22 into a lower chamber24 and an upper chamber 25, the chamber 24 being open at its bottom `and its walls terminating somewhat above the bottom plate or header 19 so as to form a passage 26 establishing communication between chamber 24 and the space 29, between tubular member 22 and casing 13. rlhevpipe 10 extends upwardly within the chamber 24 aforesaid and termi` nates below the horizontal partition 23. rEhe cylinder 22 is spaced trom the pipe 10 and Vfrom the casingi18 so as to form a chamber or liquid seal receptacle extending between the pipe 10 and the casing 18, this chamber being occupied by a body of Huid such as mercuryvindicatedat 27, which may nor- ,f g mally till the said chamber to the depth indicated at- (k), and the cylinder 22 dips-into this body ot mercury so as to form a liquid seal. rlhe chamber 25 constitutes an auxiliary receptacle Ytor liquid, said chamber 25 being at a higher level than the liquid seal receptacle and being adapted to receive and retain liquid forced up into same from the liquid .seal receptacle, as hereinafter described. Cylinder 22 is provided with ports 28 above the level of the horizontal partition 23 to establish communication between the chamber 25 and the space 29 between said cylinder and the casing 18. The upper end of cylinder 22 may be closed by a partition or head 31 located somewhat below the upper end ot the cylinder and said cylinder may have ports 30 leading from the upper chamber 25 to the space 29 between the cylinder and the casing 18, the ripper end of the cylinder 22 being spaced Jtrom the top plate or header 20 and the outlet pipe 12 extending downwardly below the top of cylinder 22 but spaced from the horizontal partition 31 so as to provide a tortuous passage t'rom the chamber 25 to the outlet pipe 12 around the partition 31 which acts as a baille plate. From the plate 31 drain pipe 32 may extend downwardly nearly to the horizontal Vpartition 23. The member 22 is provided with one or more small ports or openings 33 through which liquid may drain back gradually to the liquid receptacle'at the bottom of the casing 18, these openings being suiiiciently small to constrict and retard the flow of such liquid as hereinafter described. ln order to make the operation of the device more positive I prefer to use a sliding valve ring shown at 34 which slides vertically between the cylinder 22 and the casing 18 and normally floats on the body ot' sealing liquid. An outwardly projecting tiange 35 may be provided at the bottom ot the casing ot the cylinder 22 which normally supports valve ring 34 above the bot` tom of passage 26 so as to permit gas pressure from the inlet chamberl to be exerted beneath said valve ring to raise the same as hereinafter set forth.

ln the operation ot this form ot my invention the valve ring 34 normally floats on the mercury in the seal so that its weight is added to that of the liquid seal in obstruct ing the flow of gas. This valve may be of steel or similar material. l/Vhen the pressure difference between the inlet pipe 10 and the outlet pipe 12 is below a certain critical value the level ot' the mercury will vary but it will always maintain a liquid seal, the pressure not being suiiicient to completely displace the mercury to the point required for permitting gas to pass under the lower edge of the cylinder 22. vWhen the critical pressure diti'erence is reached which enables the gas pressure in the pipe 10 to displace the level ot the mercury between the upper part of the pipe 10'and the cylinder 22 to the level of the bottom of said cylinder', then gas will tend to pass under the bottom of the cylinder 22 and force the mercury violently upward together with the valve ring* 34 until the valve ring passes the ports 28 and occupies the vposition indicated in dotted lines at 34. The gas then tends to escape under the lower edge. of the cylinder 22 and upwardly through the'passage 29 between said cylinder and the casing 18 and through ports 28 into the upper chamber 25 and thence through ports 30 to the passage means leading to the outlet pipe 12. The mercury which is forced up from the liquid seal passes through the ports 28 into the bottom part of the upper chamber 25 and is retained by the horizontal partition 23, the space above said partition constituting an naamw;

auxiliary.l liquid receptacleV adapted? to re-V made of sufficiently small cross-sectional areaV to yensure that the amount of liquid returningfor draining back to theliquid seal receptacle is relatively smalllaud such liquidi draining back is immediately returned or blown baclr'tothe auxiliary receptacle by the outfiowing gas. Thefslide valvef34 is maintained during the above described op-r eration in position aboveI the. ports A28 as indicated Ain dotted lines in the drawing, the amount'of pressure difference required for maintaining the valve in this position beingfrelatively small. lVhen', however, the gas velocity decreases below alcertain value thevalve is allowed to falland rests onflange 35, thus forming a temporary obstruction.y The mercury or other liquid then drains back through holes 33 and re-establishes the liquid seal. This slide valve may however be omitted asthe devicewill operate without the use ofthis valve.= lVhen this slide valve, is omitted the operation is similarrto that above described, the action `yof,

the gas pressurev when the pressure. differ encefbetween Vthe inlet and outlet exceeds a certain amount,v resulting in driving the mercury or other liquid 1in the seal upwardly into the auxiliary receptacle in chamber 25L thereby permittingl relatively free passage of gas from the inlety 10 to the outlet 12. lVhen thefpressure difference between the inletandcutlet is again reduced to a certain small critical value the mercury or. other liquid drains backthrough the holes 33 .intol the liquid seal receptacle, re-establi'shing the liquid seal.

then the gas is blowingthe liquidup wardly intothe auxiliary receptacle above described and while the gas is passing through tliefdifferential relief valve int-he manner above described more or less mercury or other liquid used in theI seal .may be carried'upwardly inthe gas above-thefauxiliary receptacle, butsuch entrained liquid'is eventually removed from the gas by the. operation ofthe baffle-plate 31'andi'by'reason 0f the deflection of the gas in-its passagearound the bafl'le plate and into Ythe outlet pipe, a-nyliquid so removedlfrom the gas;

collecting in the auxiliary receptacle in chamber. 25' or being drainedin-toisaidreceptacle through the drain pipe 32.

Fig.'Y 3' shows assimpler fonmof my invert-1 tion :in which the auxiliary` liquid.4 receptacle i isforme-d in arcylindrical lmember40 mounted withinethe casing 18 insuch manner asrto'. f be fixed or retained in stationary position therein, for example-by. means of1ribs 41,y said cylindrical member having ahorizontalr partition 42 dividing the space within said member into; a. lower chamber-,43 and? an; upper chamber 44,l the latter acting; as :1n-76 auxiliary chamber for the sealingI liquid.- The lower. head 19 for the. casing 18 is. inf; this case shown as provided with a.. hub 45 extending upwardly within the casing 18 andi forming in conjunction with said casing also liquid seal chamber 47, the cylindrical member 40 extending downwardlyinto sa'idliquidf seal receptacle to forni the -liquid seal., They auxiliary liquid receptacle 44 is provided; with smallrdrainage lout-lets indicated at'481'8"x for gradually draining the'liquidbacktinto the. liquid seal when thepressure falls belowy a givenpoint. In the operation .of this form of my invention the mercury' or other sea-L, ing liquid normally occupies: the liquid seal/Wi receptacle so as tocut ofl passa-ge ofi gasl from the inlet 10 to the outlet 12,'.biut when= the gas pressure exceeds-a certaincriticab amount the liquid is blown over or'displaced` from thel liquid sealreceptacle to the auxil- 953 iary receptacle 44 wherein it is retained until the pressure falls again to a certainl critical amount,4 whereupon the liquid Will: drain. back through the holes 48 from the auxiliary receptacle 44 tothe sealing chamber 47, again cutting off passage of gas through the differentialtrelief valve.

In applying my invention to the control ofr the gas supply to ametering system having small 4and large capacity meters as shown in Fig. l the operation isvas follows: Under conditions ofrelatively small gas supply orI relatively small/ gas consumption there. will' be a small pressure differencel between the inlet pipe l and the outletipipeQ, this pres- Sure difference being determined by the pressure supplied to pipe 1 and the resistance presented by the orifice device 8, it being 1 assumed that the capacityof the pipe 2 and theme-ter 3 is sufiicient'to always maintain 115 a relatively low pressure at the outlet ofthe orifice device. Assuming that'the pressure difference under these conditionsissuch as to result in a gas How within thecapacity ofthe meter 3 the gas How Will-pass wholly. through'the branch or pipeconnections leading through the small capacity meter 3, the

differential relief valve llserving to seal ory cut off'the flow of gas through the branch including vthe large capacity meter. For this l purpose the differential relief valve 11is so constructed and proportioned as above describedas to maintain the seal'or shut olf condition as longl asrthepressuredifference between the inlet and outlet thereof does not register. tained the pressure difference between the inlet pipe l and the outlet pipe'2 becomes sufiicient to displace the liquid seal in the differential relief valve and transfer the liquid therein into the auxiliary receptacle kwhereupon the obstruction to the passage of gas through the branch including the large capacity meter is reduced to such a smallv amount that substantially the Whole flow of the gas takes place through the differential f relief valve and the large capacity meter.

As the large capacity meter 4 is adapted to register with sufficient accuracy volumes of gas corresponding to pressure differences in excess of the critical pressure difl'erencereferred to, the amount of gas delivered will besatisfactorily and effectively registered by this large capacity meter under these condi.- tions. When the supply of gas at inlet 1 is reduced so as to lower the'pressure difference to a certain value below the capacity of they meter 4 to register correct-ly the 'differential relief'valve again closes or seals this connectiomcausing the entire iiow of gas to pass through the small capacity meter 3 which is adapted to register correctly on small amounts of gas. It will be understood that the device will operate in the same manner in case the variations in pressure difference arise from variations" in the consumption or withdrawal of gas from the outlet 12 instead of from variations of supply of gas from inlet 1() or from variations at both inlet and outlet.

Various modifications may be made in the differential relief valve, especially in regard to the general application of the same to the control or transfer of connection vbetween two. meters of different capacity than shown in Fig. 1. The form of my invention shown in Fig'. 4 is similar to that shown in Fig. 3 except that the cylindrical member 50 which is provided with auxiliary liquid receptacle 51 is adapted to slide vertically within a guide ring 52 mounted ou arms 53 within the casing 18, the construction being otherwise as above described. In this case the effect of increase of pressure difference beyond a certain critical value is not only to force the sealing liquid into 'the auxiliary receptacle 51 but to raise said auxiliary receptacle, for example until it is arrested by a flange 511 thereon striking the guide means 52 on the casing 18,- thereby further diminishing the obstruction to passage of gas through the differential valve. When the pressure 4difference is again reduced a certain amount the member 50 falls by gravity to normal position as shown in Fig. et and the liquid in the auxiliary receptacle therein drains back to the liquid seal receptacle through outlets 55.

I claim:

1. A differential relief valve for gas comprising a casing, gas inlet means extending into the lower end of the casing and projecting upwardly within the casing and spaced therefrom to form a liquid seal receptacle between said upwardly projecting portion of the gas inlet means and the wall of the casing7 tubular member mounted in fixed position within the casing and having a portion extending downwardly around said upwardly projecting portion of the gas inlet means so as to extend into the liquid in the liquid seal receptacle and said tubular member being formed with an auxiliary liquid receptacle above the liquid seal Vreceptacle, said auxiliary liquid receptacle being open at its upper portion to communicate with the space between the said tubular mem-- ber and the wall of the casing to permit liquid which is forced fromthe liquid seal by the pressure of the gas from the gas inlet to pass into said auxiliary liquid receptacle, said auxiliary liquid receptacle being provided with opening means of restricted area for draining liquid therefrom back into vsaid space between said tubular member and the wall of the casing, and gas outlet means communicating with the upper portion of the chamber within said casing.

2. A construction as set forth in claim 1, and comprising in addition, liquid receiving means provided at the upper end of said tubular member and below the said gas outlet means and provided with a drainage means extending downwardly therefrom to conduct liquid collecting in said liquid receiving means to said auxiliary liquid receptacle.

3. A construction as set forth in claim 1 and comprising in addition liquid receiving means provided at the upper end of said tubular member and below the said gas outlet means and provided with a drainage means extending downwardly therefrom to conduct liquid collecting in said liquid receiving means to said auxiliary liquid receptacle, said gas outlet means projecting downwardly through the top of the casing so as to extend within said liquid receiving means provided at the upper end of said tubular member.

4. A construction as set forth in claim 1 and comprising in addition a valve ring mounted to slide between said tubular member and the wall of the casing, said tubular member being provided, at its lower portion with passage means establishing communication between the liquid seal chamber and the space between said tubular member and the wall of the casing, and said tubular member being provided at va portion thereof above said 1i uid seal receptacle with opening means esta lishing communication from said space to the interior of said tubular member above said auxiliary l] liquid receptacle, and means for limiting the downward movement of said valve ring so that it does not pass below said passage means in the lower portion of said tubular member.

In testimony whereof I have hereunto sub- 10 scribed my name this 21st day of December, 1925.

THOMAS H. CLEMENTS. 

